A ball is thrown from a height of 157 feet with an initial downward velocity of 9ft/s. The ball's eight h (in feet) after t seconds is given by the following.

h=147-9t-16t^2

How long after the ball is thrown does it hit the ground?
Round answers to the nearest hundredth

Question

A ball is thrown from a  height of 157 feet with an initial downward velocity of 9ft/s. The ball's eight h (in feet) after t seconds is given by the following.

h=147-9t-16t^2

How long after the ball is thrown does it hit the ground? 
Round answers to the nearest hundredth

anonymous · Answer

@hartnn

anonymous · Answer

$$-16t^2-9t+147=0$$ solve for $t$